can a partition be loaded from file?

Hi,
I have a question that if a partition can be loaded from a file?
A table in the database is partitioned, and each partition is saved to a separate tablespace, so each located in a separate directory. We want to transfer the data in a specific partition (a directory with files in it) to a remote machine then load this partition to the db for processing. The remote DB has the same db schema to the local machine. and the data in this table doesn't depend on other tables. I'm not sure if it is workable. we can stop the database when doing backup (but not the database engine, Postgresql process) for data consistency.
If it is not workable, does the COPY TO file function is the best solution for this situation?
Thanks!

BR,
Emmett Zhang